[1] OSPED BELLARIA,SEZ ANAT ISTOL & CITOL PATOL MARCELLO MALPIGHI,DIV NEUROSURG,I-40139 BOLOGNA,ITALY
[2] OSPED BELLARIA,DIV NEURORADIOL,I-40139 BOLOGNA,ITALY
[3] UNIV BOLOGNA,DEPT CLIN RADIOL & ANAT PATHOL,SECT ANAT PATHOL MARCELLO MALPIGHI,BOLOGNA,ITALY
[4] UNIV PAVIA,INST PATHOL ANAT,VARESE,ITALY